package com.example.reggie.filter;


import com.alibaba.fastjson.JSON;
import com.example.reggie.common.BaseContext;
import com.example.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Slf4j
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    //路径匹配器
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        log.info("拦截到请求：{}",request.getRequestURI());

        //1.获取本次请求的URI
        String requestURI = request.getRequestURI();

        //定义不需要处理的请求
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login",
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };

        //2.判断本次请求是否需要处理
        boolean check = check(urls, requestURI);


        //3. 如果不需要处理，则放行
        if (check){
            log.info("本次请求{}不需要处理", requestURI);
            filterChain.doFilter(request, response);
            return;
        }

        //4 -1. 判断登入状态，如果已登入，则放行
        if (request.getSession().getAttribute("employee") != null){
            log.info("用户已登入，用户id为：{}", request.getSession().getAttribute("employee"));

            //设置用户id值放入BaseContext中
            BaseContext.setCurrentId((Long) request.getSession().getAttribute("employee"));

            filterChain.doFilter(request, response);
            return;
        }
        //4 -2. 判断用户登入状态，如果已登入，则放行
        if (request.getSession().getAttribute("user") != null){
            log.info("用户已登入，用户id为：{}", request.getSession().getAttribute("user"));

            //设置用户id值放入BaseContext中
            BaseContext.setCurrentId((Long) request.getSession().getAttribute("user"));

            filterChain.doFilter(request, response);
            return;
        }

        log.info("用户未登入");
        //5. 如果未登入则返回未登入结果，通过输出流的方式向客户端页面相应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 路径匹配，检查本次请求是否放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls, String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match){
                return true;
            }
        }
        return false;
    }
}
